Electric water-heater.



L. F. PARKHURST.

ELECTRIC WATER HEATER.

APPLICATION FILED NOVI 23| I9I6.

1,270, 1 98. Patented June 18, 19m

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52N l I /4 paf I I Inventor:

' Leon F.' parkhuT-St 30 /2 IOS H i S aqttorrweld.

UNITED sTATEs PATENT oEEroE.

LEON F. PARKHURST, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC WATER-HEATER.

Application filed November 23, 1916.

Ton/ZZ w71 um it may concern:

Be it known that, I, LEON vF. PARKHURST, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Electric later-Heaters, of which the following is a specification.

My invent-ion relates to an electric heating device and more particularly to an electric water heater and has for its objectthe improvement of a device of this character.

ln accordance with my invention, a body of metal which forms a good thermal path for conveying the heat from the heating unit to the water is cast directly around the sheathed wire unit, thereby greatly adding to the efficiency of the device. At the same time a simple and compact device is provided and one which is readily connected to and disconnected from the standard pipe fittings, with which a kitchen boiler is usually provided.

Another feature of my invention resides in the provision of a. casing or housing for the terminals of the sheathed Wire which is integral with the metal in which the sheathed wire is cast.

Other novel features of.m invention will be apparent from the speci cation and will be particularly pointed out in the claims.

I have shown one embodiment of my invention in the accompanying drawing in which Figure 1 is a plan view of an electric heater with the cover for the terminal boX removed; Fig. 2 is a longitudinal section of the heater shown in Fig. l; Fig. 3 is a sectional view of a piece of sheathed .wire and the terminal therefor which is suitable for the purposes of my`invention; Fig. 4 is a side view partially in section showing another form of heater in which the terminal box for my invention may be embodied; and Fig. 5 is a detailed view showing a section of one of the plates on which the sheathed wire is mounted prior to being cast into the heater of Fig. 4.

Referring now to the drawings, and first to Figs. 1 and 2, which disclose the preferred form of my invention, is a metal tube through which the water or other liquid passes. This tube is preferably formed of copper, as I have found in practice that deposits from the water, and particularly alkaline deposits, are less likely to i Specification of Letters Patent.

Patented June 18, 1918.

Serial No. 133,071.

form on copper than on other materials, and any deposit that may occur is more readily removed. This pipe is screw threaded at its ends 10a for connection with other pipes or standard fittings such as those with which a circulation kitchen boiler is usually provided. A coil of sheathed wire 11 comprising a core resistance wire 12, inclosed in a metal sheath 13 with an intervening layer of insulating material 14, is coiled around the pipe 10 and provided with enlarged terminals 15 of the character disclosed in Patent #1,093,512, whichv was issued to Willis R. Whitney'on April 14, 1914, the enlarged portions of the core, sheath, and insulating material being indicated by the reference numerals 12, 13a and 14 respectively. The tube with the/ surrounding sheathed wire and with the terminals extending to one side, is then placed in a suitable mold and a metal jacket 16 having a lower melting point than that of the tube, is cast around the sheathed wire and the tube, and consti? tutes la thermal path of good conductivity for carrying the heat from the resistance unit to the water. When the tube in the heater is formed of copper, then the castjacket may consist of aluminum, since the lmelting point thereof is lower than that of copper and this material is at the same time a good conductor of heat. A casing or housing 17 provided with a suitable opening 18 for the reception of the terminals of the sheathed Wire and for the connections therefrom to the supply conductors, is preferably cast integral with the jacket 16. An insulating slab or plate 19 is preferably provided in the bottom of the opening in t-he terminal boX, and is formed with openings 20 into which the terminals of the sheathed wire are brought. The insulating slab 19 is also provided with suitablegrooves 21 leading from the openingsA 20 to suitable openings in the side of the terminal box, as indicated in Fig. l, for the reception of the ends of the supply conductors and the connections therefor to the sheathed Wire terminals. Suitable clips or plates 22 are electrically connected to the outer ends of the core terminals of the sheathed wire and are preferably brazed thereto and the terminals 23 at the ends of the supply conductors 24 may be connected to the clips 22 by means of inding posts 25 of usual form. A second insulating plate 26 may, if desired, be

interposed hetvveen the piate i9 and the cast material of the jacket i6. The insulating piates i9 and 26 may be held in place by screvvs 27. The terminal box is closed by a cover 28 which engages' lugs 29 formed in the inner corners oi the terrninai box and 1which are depressed belovv the upper iace oit the terminal bor suciently to ailovv the cover to drop iiush vvith or slightly belovv the top of the terminai bon.

'in Figs. 4: and 5 l. have shown certain {eatures` oi my. invention embodied in a vvater heater of a slightly diferent type., dn this heater lthe metal of the pipe, vvhich/ terms the passage for the Water, is cast around the sheathed vv-ire resistance ineinber. in this case, the sheathedl Wire is rst coiled upon a plurality or' plates 30,*provided with suitable openings di, the sheathed Wire being secured in place by ngers 32 which extend over the sheathed Wire and hold the same in position. 'lhe terminai bei: 33 is here aiso'rnade integrai with "the cast-'materiali surrounding the sheathed Wire; the saine as in iigs. i and 2, ln this cran of heater, the connection with other to represent the best pipes maybe made at the sides7 as at 34.

lWhile in Figs. i and 5 l. have shown rny invention embodied in a device in which the casting around the sheathed vfire also torres a passage tor thevvateni prefer the structure shown in Figs. i 'and 2, inasmuch as the copper tube is never porous to the Water as is likely to he the case with a teaming, due to the blovv process.

iin accordance with the. provisions of the patent statutes, i. have described the principle oi? operation ot my invention, together 'with the apparatus which i novv consider embodiment thereof; but ii desire to have it understood that the apparatus shown is' only illustrative, and be carried out by What iiclaiin as nevv and desire to secure by LetterslPatent ot the United Statese is 2,--

l i. The method of making an electric heating device comprising sheathed Wire formed vvith' a resistance core inclosed in a metal sheath with an intervening layer or 'insulat ing material, lwhich consists in Winding the sheathed Wirefon a nietal tube and then casting a metal jacket around the sheathed Wire and the tube. p y v 2. An eiectric heating' device comprising l hoiesrormed during the casting rnarod a metal tube surrounded by 'a sheathed re:

sistance Wire formed of a core Wire inciosed in a metal sheath with an intervening` layer of insulating'V inmerial, and a *jacket coinposed or a inateriai having a iovver melting point than said tube cast around the tube and the `sheathed Wire.

fr An eiectric heating; device comprisiug` a metal tube surrounded by a sheathed re-f sistance Wire formed of a core Wire inclosed in ya instal sheath with' an intervening iayer lor insulating material, and a instal jacket cast around the tube and the resistance vvire9 the terminais for the sheathed Wire being brought through the jacket.,

6. fin electric heating'- device comprising a copper tube surrounded hy a sheathed resistance vvire comprising a core Wire inv ciosed in a instal sheath with an intervening `layer of insulatingI materi.al,"and a jacket ,of aluminum cast around Vthe tube and the sheathed vvire. 7 electric heating device comprising a metal tube, a sheathedresistance Wire coniprising a core Wire inclosed in a metal sheath with an intervening iayer of insuiatl ing material Wound on the tube, and a inetal jacket cast around the tube and the residence Wiree the ends or the tube projecting beyond the casting and formed ior connection vvith other pipe.,

8. An eiectric heating device comprising a metal tube, a sheathed Wire having a core Wire inciosed in a metal sheath with an interveningliayer of insulating material, and a metal jacket cast around the tube and the sheathed wire, the casting being provided `with an integral housing; for the terminals Y vof the sheathed Wire. l

in Witness whereof, it have hereunto set niy handthis'22nd day or November i916.

LEUN l?. PARKHURST., 

